Chaos in the world of automation: An overview for users.

In the world of automation many different standards, systems and components from a wide number of manufacturers encounter each other. This diversity often leads to the user losing track of what there is. The development of the Internet of Things and plans for total networking mean that the market is continually subject to highly dynamic changes. It is no easy task to choose the »right« system to meet one's needs.

Many end users and integrators usually prefer one system or a »favourite manufacturer« which is then used exclusively. This is not necessarily always the best choice. Qualitative criteria can significantly optimize and simplify the selection process.

Open versus proprietary systems

It is very important to have a clear picture of whether an open or a proprietary system is to be used and what the advantages and disadvantages of each might be.

With an open system the manufacturers, developers and any other interest groups have insight into the standard and work actively in its further development. In addition open systems usually include many interoperable devices from different manufacturers which, in the best case scenario, work together perfectly. Publication of a standard means that a critical examination by outsiders is possible. This is only negative if security-related areas such as encryptions are openly accessible.

A proprietary system is manufacturer-specific so that only the manufacturer and a selected group of members have access to the system specifications and development. Within such systems usually only a certain number of manufacturer devices is available. If the products used, or devices with specific functions, are no longer available, there is no alternative as there is with an open system.

The second important criterion in this context is the number of manufacturers and devices on the market. There is one relatively simple rule of thumb: the more manufacturers involved in a standard the more likely it is that there will a wide range of devices available on the market. Therefore, the devices are more likely to be available for longer on the market than is the case with small or closed systems.

Medium of transmission

An important role in the communication of components is played by the transmission medium. The most widespread are twisted pairs (two-wire lines), existing electricity cables or radio. The established standards cover a wide number of these communication media. Others are restricted to one or just a few. However, not all media are of the same quality. The more media available, the more flexibly a standard can be used. The best transmission quality is provided by a wired system when the wiring has been carried out professionally. This is why this is usually used in new buildings. Fitting a wired system at a later date is both complex and expensive which is why the radio medium is often used in existing buildings. Automation components can then be distributed as desired throughout the building or the project. However, this medium also bears risks: firstly, it is »open« and outsiders can intercept and influence unencrypted data transfer; secondly, other radio systems or components can place a heavy strain on the medium or disturb it to such an extent that a whole system can intermittently fail. Many systems such as Zigbee or EnOcean, which typically transmit via radio, provide encryption and collision mechanisms to prevent such problems.

Installation, commissioning and maintenance

Automation systems can be divided into two types of installation: the typical decentral systems where the components are installed separately in the individual rooms of a building; and the central systems where all components are accommodated in one location (e.g. the control cabinet). The wiring is then led from there into the different areas and rooms and thus to the user. The installation costs can differ greatly since the wiring costs for a decentral system can be substantially lower. Another aspect is that the central or decentral location of the components affects how easy maintenance is and how much the device costs. Maintenance work and the replacement of individual components is quite simple in centrally installed systems; usually an infrastructure is provided for this. In decentral systems single components may be »hidden« in false floors, suspended ceilings or in recessed fittings behind a cover plate. This affects how to localize the components and to gain access to them. Many common standards and systems allow both types of installation and a setup which is a mixture of central and decentral is possible.

When commissioning there is a very distinct difference between the systems. KNX focuses on one uniform software which is the same for all manufacturers and users. LON has several parallel tools and BACnet enables free designing of the software for each individual manufacturer. The latter, however, makes it difficult to maintain and commission the installation.

Simple access to the installation is of great importance for the end user. Proprietary manufacturers usually provide tablet visualization or something similar. In this way the user can, when necessary, administrate his own system and make certain modifications himself without having to involve an external integrator.

Automation's field of application

In the project phase consideration must be given to where the automation is to be located. Are we dealing with private detached residences or large purpose-built structures and properties? A decisive factor is whether a specific area or just one technology is to be automated or the whole building. For smaller projects, systems such as KNX are recommended which cover automation in rooms with all the required functions. These include, for example lighting, shading, air-conditioning and security. Proprietary system such as free@home from Busch Jaeger or enet from Jung & GIRA are also very interesting for this purpose. These systems have attractive prices and are, to some extent, easier to use. Before making a decision it is important to check that the selected system includes the functions required for the project. Other automation systems such as DALI or SMI are intended for special tasks. DALI is a bus for lighting control and SMI for controlling shading installations. An overview of the possibilities of the individual standards can make an invaluable contribution to the selection of the system and the components.

Selecting a system and looking into the future

When automating a project, it is very important, first of all, to define the aims. Does the project merely involve a special function such as automating lighting and shading functions? In this case, special standards provide an optimal and adequate scope of functions. If, however, the intention is to add to the installation in the future, then a standard which offers this option should be used from the very beginning. Since there can be no one universal solution, the criteria mentioned above may help in selecting the right or best system for one's personal needs. An analysis of the requirements during the planning stage is an absolute must.

What effect will the Internet of Things and total networking have on the continuing existence of individual automation standards? The umbrella organisations are prepared for this and are developing systems in this direction. Today it is already possible to integrate all the common systems into existing IP networks and thus into the Internet. However, it is not possible here to make any kind of binding statement. When choosing a system, it is advisable to keep an eye on the advances being made within the individual standards.